Circuit-arrangement for energizing relays



PULSES Oct. 5, 1954 TEST WIPER .6

MS CONTROL DEVICE DIAL DEVICE VOL TA 6E COMPARISON R. B. BUCHNER CIRCUIT-ARRANGEMENT FOR ENERGIZING RELAYS Filed March 1, 1952 O7 ARY MAGNET H) Y A (SELECTOR) CUT-0F F BIAS INVENTOR Robert Bertold Buchner Agent Patented Oct. 5, 1954 CIRCUIT i-'-ARRANGEMENT .TFORH ENERGKZING RELAYS."

Robert Bertold Buchner, lriiilversum, Netherlands", assignor to Hartford Nationai Bank and Trust Company, Hartford, Comn, as trustee Application. March-1, 1952,.Serial -N o..-274,-383 7 Claims priority, application Netherlands March 28, 1951 3 Claims. I Y

The invention relates to a circuit-arrangement for energizing a relay, whosewindingis included in an output circuit of a discharge tube.

Such circuit arrangements are :used, for exampie, in a device for-numerical adjustment of :a selector by a method in which voltages or cur rents are tested by. electronic. means and in which, for example, the relay controls the movement of the selector. It is, in general, desirable for the relay to be energized very rapidly when the tube becomes conductive.

In known circuit-arrangements. of this kind, the relay exhibits a delayed energization, since, when the tube beco-mesconductive; a self-inductance voltageis produced across the winding .of

the relay, which strongly reduces the anode voltage of the tube and thus opposes the rapid in crease in energizing current.

The invention provides a circuit-arrangement in which the relay is considerably more rapidly energized than in the known circuit-arrangements.

In the circuit-arrangement according to the invention an inductor is connected in series with the winding of the relay and is also inducted in the output circuit of a second tube whose controlelectrode is coupled with the output circuit of the first tube in a manner such that when the first tube becomes conductive, the second tube is cut-off.

Tests have proved that by the measure proposed the magnetisation time of a relay may be reduced, for example, from 1.5 msecs. to 0.2 msec.

In order that the invention may be more clearly understood and readily carried into effect, it will now be described more fully with reference to the accompanying drawing, in which one embodiment is shown.

In a diagrammatical and simplified from the figure shows a circuit-arrangement for the numerical adjustment of a selector K by a voltagecomparison method under the control of a register Rey. The marking contacts brushed by the test wiper b of the selector are marked by direct voltages vxl, VXZ, VXB, and so on, the values of which are characteristic of the number or digit, which is associated with the corresponding outlet. The register Reg" receives the dial pulses, which may be emitted, for example, by a subscriber and adjusts the marking switch MS correspondingly in a manner known per se and not further described. The outlet contacts of the switch MS are marked by direct voltages, the values of which correspond to the various marking voltages of the marking contacts of the selector K. After the 2i dial signals have been: received, the contact "0 is closed :by means (not shown), so 1 that the rotary magnet YD. of theselector is magnetized in series with theecontact o and'themake contact t of the testing=rrelayo- ;T,: which zis'snorrnally energized, and the selector begins to-move; During the movement of the tswitch the device OI which may be of akind known per se compares the voltage of the test: wiper b of .thexselector inthe register with the voltage ofrthe'wiper of the marking switch. As long as the test wiper bis in contact with marking contacts ofunwanted outlets, the voltages are unequal and the device OI supplies a comparatively high voltage to the control-grid Q1 of the tube B1, so that the tube B1 is conductive. The testingrelay T, of which a winding is included in the anode circuit of the tube B1, is then energized and the making contact if is closed in the energizing circuit of the rotary magnet D.

As soon as a wanted outlet is found, the voltages of the wiper b of the selector and of the wiper of the markingswitch MS are equal and device OI supplies a voltage to the-control grid 1 of tube B1 to reduce the voltage of this control grid to an extent at which the tube Br is cut-01f and the relay T is deenergized. The make contact if breaks the energizing circuit of the rotary magnet D and the selector is halted.

In practice it may occur that during the testing movement of the selector the device OI accidentally finds voltage equality for a short time, for example, during the transition of the wiper b to a next following contact or owing to bad contact between the test wiper and the marking contact, due to a leap of the selector wiper. The tube 131 is then cut-ofi and the relay T is deener-- gized, so that the make contact t opens the energizing circuit of the rotary magnet D. The next instant, however, the voltages are again unequal and the device increases the voltage of the control-grid g1 again to such a value that the tube B1 becomes conductive. It is desirable for the relay T to respond again rapidly and to close the energizing circuit of the rotary magnet D before the rotary magnet D has been demagnetized to such an extent that the selector stops. However, with an increase in current passing through the winding of the relay T an inductance voltage is produced therein, so that the anode voltage of the tube B1 decreases strongly and the current passing through the relay cannot increase rapidly enough to energize this relay before the rotary magnet has been deenergized.

In order to obviate this disadvantage particular measures are taken in the circuit-arrange ment, so that the relay T can be energized rapidly. An inductor L is connected in series with the relay winding and is furthermore included in the anode circuit of an auxiliary tube B2. The screen grid on of the tube B1 is connected to a first tap of the potentiometer R1, R2, R3, connected between the supply points V1 and V2. The control-grid 3 of the tube B2 is connected to a second tap of this potentiometer positioned below the first tap thereon. If the tube B1 is cut-01f, the screen grid g2 is at a comparatively low potential, so that the control-grid 93 of the tube B2 has such a low Voltage that the tube B2 is conductive. Then a certain current passes through the inductor L and the tube B2, but not through the tube B1 and the winding of the relay T. If the tube B1 is opened, an inductance voltage is produced across the winding of the relay T, decreasing the voltage of the anode; at the same time, an inductance voltage is produced at the inductor L, since because of the reduction of the voltage of the screen grid g2 and the associated drop of the voltage of the control-grid ya, the tube B2 is cutoff and the current passing through the inductor L cannot flow through the tube B2. The inductance voltage of the inductor L opposes that across the winding of the relay T and increases the voltage of the anode of the tube B1, so that the relay T is energized rapidly.

What I claim is:

1. Apparatus for actuating a relay provided with a winding in accordance with an applied control voltage comprising first and second electron discharge tubes each having a cathode, a control grid and an anode, an inductance connected in series with the winding of said relay, the end of the winding remote from said inductance being coupled to the anode of the first tube, the junction of said winding and said inductance being coupled to the anode of said second tube, means to apply positive potential relative to the cathodes of both tubes to the end of said inductance remote from said relay means normally to maintain said first tube non-conductive, means to apply said control voltage to the control grid of said first tube whereby said first tube is rendered conductive when said control voltage attains a predetermined value and said relay is energized, and means coupling the anode of said first tube to the control grid of said second tube to render said second tube non-conduciive when said first tube conducts whereby the self-inductance voltages produced across said inductance and said relay oppose each other and slid relay is rapidly energized.

2. Apparatus as set forth in claim 1 wherein the inductance and the relay winding have reactive values at which the self-inductance voltages of said inductance and said relay winding cancel each other.

3. Apparatus for actuating a relay provided with a winding in accordance with an applied control voltage comprising first and second electron discharge tubes each having a cathode, a control grid and an anode, said first tube also having a screen grid, an inductance connected in series with the winding of said relay, the end of the winding remote from said inductance being coupled to the anode of said first tube, the junction of said winding and said inductance being coupled to the anode of said second tube, means to apply a positive potential relative to said cathodes to the end of said inductance remote from said relay and to said screen grid, means normally to maintain said first tube non-conductive means to apply said control voltage to the control grid of said first tube whereby said first tube is rendered conductive when said control voltage attains a predetermined value and said relay is energized, and means coupling the screen grid of said first tube to the control grid of said second tube to render said second tube non-conductive when said first tube conducts whereby the self -inductance voltages produced across said inductance and said relay oppose each other and said relay is rapidly energized.

No references cited. 

